- 300ml semi-skimmed milk
- 1 tbsp caster sugar
- ¼ tsp vanilla extract
- 1kg ice
- 6 tbsp rock salt
- hundreds and thousands, to serve
You will need
- 2 medium zip-seal freezer bag
- 1 large zip-seal freezer bag
- sticky tape
Place the milk, sugar and vanilla into the doubled-up medium zip-seal bags. Close and secure with sticky tape if the seal isn’t strong. Tip the ice and salt into the large bag, then place the smaller bags inside the larger one, and seal well.
You will need to keep the bags moving for 10-15 mins to freeze the milk. Gently throw the bag from hand to hand or take turns shaking it – it’s a good idea to wear gloves to keep your hands warm! Remove the ice-cream bag, open and scoop into bowls. Sprinkle with hundreds & thousands.
The science bit
Under normal circumstances, water freezes at 0C. But adding salt to the ice lowers the temperature to -10C, meaning the milk freezes in minutes.